Paws and claws: Protecting livestock with pet biosecurity

Many livestock parasites and diseases are not fussy about what animal they infect, whereas some depend on carnivores such as dogs or cats to complete their lifecycle.

Treating parasites in your petscan have a direct impact on livestock health.

This article is a general overview of pathogens that can spread between livestock and dogs or cats.

Dogs

Tapeworm

The dog hydatid tapeworm is important for livestock farm biosecurity as it infects sheep and goats – causing hydatids which may be responsible for offal and carcase downgrading at the abattoir. Tapeworm eggs can also stick to a dog’s coat and so humans can pick up tapeworms directly from touching them, especially children who may be less fastidious than adults about hand cleanliness or what they put in their mouths! Dogs are part of the life cycle for this parasite so treating them ‘breaks the chain’ of your livestock becoming infected.

It is easily treatable with tapeworm treatment – give regularly as per the label instructions. Products containing praziquantel are effective. Please do make sure to check that ‘tapeworm’ (Echinococcus) is specifically listed on the label, as many ‘multi-parasite’ products do not cover it (i.e. the type that claims to treat ticks, fleas and worms). This might seem to be an oversight however the commonest way for urban dogs to pick up tapeworms is actually from fleas (which carry their eggs), so the ‘flea prevention’ part of these products is enough to keep town dogs safe. Farm dogs however live much more closely with other species (and their delicious faeces!) so they need additional tapeworm prevention.

The other aspect to this is to prevent dogs from scavenging carcasses. If you do wish to feed them meat, ensure it has been thoroughly cooked or been deep-frozen (below -20^oC) for at least 2 days. This reduces but does not entirely remove the risk of tapeworm transmission.

Foxes and wild dogs can also spread tapeworms. Preventing scavengers from accessing carcases is an important part of farm biosecurity.

Other gut parasites

Dogs can become infected with many other livestock gut pathogens, thanks to their adventurous appetites. These can include parasites such as Giardia and Cryptosporidium. The result will generally be persistent and often-violent diarrhoea. Prevent dogs from eating livestock faeces, especially at times of high risk of these pathogens being excreted by livestock (e.g. around lambing).

Ticks

The risk posed from ticks depends on the region that you are in – the type of tick present, and any diseases that those ticks may be carrying.

Dogs are not part of the life cycle of cattle ticks, which are ‘one host’ ticks.

Bush ticks can attach to dogs. In such a way, ticks carrying pathogens like Theileria may ‘hitch a lift’ onto your property.

The deadly east coast paralysis tick produces toxins that can directly kill dogs from just a single tick attaching, producing signs from slight ‘wobbliness’ to inability to walk and difficulty breathing. Ticks therefore need regular PREVENTION, to ensure ticks are killed as soon as they attach.

Keep your dogs protected with regular tick prevention. Check the label for required frequency. Ask your vet so that you can be sure you are using one of the newest products on the market – similar to livestock parasite products, the longer a chemical has been in use, the greater chance of parasites being resistant to it.

Going through their coat with a tick comb is time-consuming but effective if done thoroughly. Be aware that ticks also like to hide in awkward places (e.g. ear folds or between toes).

Leptospirosis

If they have access to surface water (especially stagnant water such as ditches or small ponds) dogs can be at risk of leptospirosis. This a potentially-lethal bacterial infection which in many areas is present in the rodent population and can be spread in rodent urine to infect most animals including humans. Illness can be severe. Leptospirosis is preventable by regular vaccination in areas where it occurs (check with your vet).

Cats

Domestic cats should also be prevented from scavenging and should be wormed regularly, as for dogs.

Cats are the major player in the life cycle of the parasite Toxoplasma gondii. T. gondii can infect most warm-blooded animals, but it can only replicate in cats. On farms, it normally involves cats and sheep (or goats), with sheep becoming infected from eating pasture or feed contaminated with cat faeces. Cats become infected from eating carcasses, and in turn T. gondii multiplies within and is spread by the cat.

T.gondii can also infect humans – in immunocompromised people and pregnant women, the consequences of the disease (toxoplasmosis) can be devastating.

Prevention is by breaking the lifecycle – keep cats off livestock pasture and fodder and prevent cats from scavenging carcasses. Containment is ideal. T. gondii in cats is NOT covered by worming treatments.  Feral cats should be controlled.

Another parasite that cats and sheep share is Sarcocystis. It is found only in some regions of Australia, e.g. Tasmania and Kangaroo Island, but is again prevented through stopping cats becoming infected (via scavenging carcasses) and contaminating pasture or feed.

Author: Dr Lindsay Hamilton, Biosecurity Coordinator, Animal Health Australia